Replication Guide for Police Violence and Public Perceptions:  An Experimental Study of How Information and Endorsements Affect Support for Law Enforcement

One main dataset was used for the analyses in Police Violence and Public Perceptions.  The Excel file, police1.xlsx, contains the responses to the survey we conducted during the fall of 2018.  The text of the survey questions is available in the Online Appendix.  The Excel data file and accompanying codebook, police1_codebook.pdf, can be found in the �1903 JOP� folder.

The following instructions will allow interested users to reproduce all tables and figures in the article and online appendix.  We have included a zipped file, Police_combined.zip, which includes all files in the dataverse and retains our original file structure.  In running the command files, the user will need to correct the file paths, locating each file as appropriate.  All files referred to in this document and uploaded to the JOP Dataverse are listed and described herein.

All of the analyses in the article and supporting information were performed using STATA 13.1.  All of the analysis datasets are saved as text files, Excel (Microsoft Excel 2010) files or STATA files.


Tables and Figures in the Article and Online Appendix

Police Violence and Public Perceptions Table 1 and OA Table A2

The STATA do file, Tables 1 and A2.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics, reshapes respondents� blame rankings from wide to long form, and estimates a rank-ordered logit model of respondents� attributions of blame for the Stephon Clark shooting in 2018.  The coefficients and standard errors from the model are reported in Table A2.  Below the model are commands that conduct Wald chi-square tests for blame coefficients and differences in blame coefficients calculated from the rank-ordered logit model in Table A2.  The blame coefficients and results of the Wald chi-square tests are summarized in Table 1.


Police Violence and Public Perceptions Figure 1 and OA Tables A3, A4 and A5

The STATA do file, Tables A3 A4 and A5.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics and trust in the police, and estimates logit models of respondents� trust in leaders of the Sacramento Police Department and trust in their local police officer association.  The coefficients and standard errors from these models are reported in Table A3.  Below each model are commands that use the CLARIFY package to generate predicted probabilities and first differences.  These predicted probabilities and first differences are saved in two log files (trust_spd.log and trust_poa.log) and an Excel dataset (Fig 1 trust simqi.xlsx).  These predicted probabilities and first differences and the critical intervals associated with them are summarized in Tables A4 and A5.  The predicted probabilities are plotted in Figure 1.

The STATA do file, Figure 1.do, imports the Excel dataset, Fig 1 trust simqi.xlsx, containing predicted probabilities generated from the logit models in Table A3 using CLARIFY, and plots these values.


Police Violence and Public Perceptions Figure 2 and OA Tables A6 and A7

The STATA do file, Tables A6 and A7.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics and candidate support, and estimates ordered logit models of respondents� support for sheriff and district attorney candidates favored by local police officer associations.  The coefficients and standard errors from these models are reported in Table A6.  Below each model are commands that use the CLARIFY package to generate predicted probabilities and first differences.  These predicted probabilities and first differences are saved in two log files (law_sheriff.log and law_da.log) and an Excel dataset (Fig 2 support simqi.xlsx).  These predicted probabilities and first differences and the critical intervals associated with them are summarized in Table A7.  The predicted probabilities are plotted in Figure 2.

The STATA do file, Figure 2.do, imports the Excel dataset, Fig 2 support simqi.xlsx, containing predicted probabilities generated from the ordered logit models in Table A6 using CLARIFY, and plots these values.


Police Violence and Public Perceptions Figure 3 and OA Tables A8, A9 and A10

The STATA do file, Tables A8 A9 and A10.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics and candidate support, and estimates ordered logit models of respondents� support for sheriff and district attorney candidates favored by local police officer associations.  The coefficients and standard errors of these models are reported in Table A8.  Below each model are commands that use the CLARIFY package to generate predicted probabilities and first differences.  These predicted probabilities and first differences are saved in two log files (law_sheriff_trust.log and law_da_trust.log) and an Excel dataset (Fig 3 support simqi.xlsx).  These predicted probabilities and first differences and the critical intervals associated with them are summarized in Tables A9 and A10.  The predicted probabilities are plotted in Figure 3.

The STATA do file, Figure 3.do, imports the Excel dataset, Fig 3 support simqi.xlsx, containing predicted probabilities generated from the ordered logit models in Table A8 using CLARIFY, and plots these values.


OA Table A11

The STATA do file, Table A11.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics, and tabulates mean values for the entire sample and the treatment and control groups from experiment 1 and experiment 2.  In addition, Table A11.do conducts difference-of-means tests to assess the efficacy of the randomization process for both experiments.  The mean values and results of the difference-of-means tests are reported in Table A11.


OA Table A12

The STATA do file, Table A12.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics, and tabulates frequencies for the entire sample, each county and the non-Sacramento sample.  The frequencies are reported in Table A12.


OA Tables A13, A14, A15 and A16

The STATA do file, Tables A13, A14, A15 and A16.do, imports the analysis dataset, police1.xlsx, recodes variables for respondent characteristics, reshapes respondents� blame rankings from wide to long form, and estimates two rank-ordered logit models of respondents� attributions of blame for the Stephon Clark shooting in 2018.  The first re-estimates the model in Table A2 while adding demographic controls.  The second re-estimates this model with demographic control for white respondents.  The coefficients and standard errors from these models are reported in Table A13.  Below each model are commands that conduct Wald chi-square tests for blame coefficients and differences in blame coefficients calculated from the rank-ordered logit models in Table A13.  The blame coefficients and results of the Wald chi-square tests are summarized in Tables A14, A15 (for all respondents) and A16 (for white respondents).










